Vehicle suspension system

ABSTRACT

A vehicle suspension comprising a frame ( 3 ) and a pair of levers ( 11 ) carried by the frame on opposite sides thereof. Each lever is pivotally mounted on the frame for swinging movement on an axis intermediate opposite ends of the lever transverse to the frame. The suspension includes a pair of beams ( 17, 19 ), one extending forward from one of the levers and the other extending forward from the other lever, each of the forwardly-extending beams having a pivotal connection with the respective lever forward of the lever axis and having a support for a forward axle. The suspension also includes a pair of beams, one extending rearward from the other lever, each of said rearwardly-extending beams having a pivotal connection with the respective lever rearward of the lever axis and having a support for a rearward axle.

BACKGROUND OF THE INVENTION

[0001] This invention relates generally to vehicle suspensions, and moreparticularly to an improved suspension for tandem-axle trucks.

[0002] The present invention is especially suited for beam-typesuspensions where the axles of a tandem-axle truck are supported bybeams pivoted to hangers on opposite sides of the frame of the truck.Springs (e.g., air bags) on the axle ends of the beams support theframe. Ideally, such suspensions are designed to be as lightweight aspossible, to provide a soft ride and adequate roll stiffness orstability, that is, resistance to the tendency of the truck body to rolllaterally during cornering, to provide an even distribution of the loadover the wheels as the truck travels over bumps and as it turns, toprovide good braking, to minimize torque applied to the axle as thevehicle encounters bumps in the road, and as it turns, and to eliminateso-called “dock walk”, which is the tendency of a vehicle to move awayfrom a dock as it is being loaded. While certain prior designs haveachieved some of these objectives, it has been usually been at thesacrifice of other objectives. There is a need, therefore, for asuspension which represents an improvement over prior suspensions.

SUMMARY OF THE INVENTION

[0003] The suspension of the present invention is an improvement whichis intended to meet most if not all the aforementioned objectives. Thesuspension provides a high degree of roll stability and, in someembodiments, substantially eliminates dock walk. The suspension isdesigned to reduce torque on the axle to increase axle life, and ingeneral has components of greater durability. The suspension provides asoft ride performance equal to or better than existing air systems. Insome embodiments the suspension provides load equalization under brakingso only one of the two axles requires ABS sensors. The suspension isequipped for easy axle alignment, either at the factory or in the field.The suspension can be used as a tandem road trailer unit withoutmodification. The system is light in weight and can be fabricated at lowcost. Further, the suspension can be used with existing trailers andaxle and brake systems. The suspension is also designed to reduce axlestress so that the axles of the suspension can be made of lightermaterial, if desired.

[0004] In one embodiment, a vehicle suspension of this inventioncomprises a frame for support of a vehicle, the frame having a forwardend, a rearward end and sides. A pair of levers is carried by the frameintermediate the ends of the frame, one at one side and the other at theother side of the frame. Each lever is pivotally mounted with respect tothe frame for swinging movement on an axis intermediate opposite ends ofthe lever transverse to the frame. The suspension includes a pair ofbeams, one extending forward from one of the levers and the otherextending forward from the other lever. Each of the forwardly-extendingbeams has a pivotal connection with the respective lever forward of thelever axis and has a support for a forward axle. The suspension alsoincludes a pair of beams, one extending rearward from one of the leversand the other extending rearward from the other lever, each of therearwardly-extending beams having a pivotal connection with therespective lever rearward of the lever axis and having a support for arearward axle. A forward pair of springs is provided, each interposedbetween a respective forwardly-extending beam and the frame. A rearwardpair of springs is also provided, each interposed between a respectiverearwardly-extending beam and the frame.

[0005] In another embodiment, the suspension comprises a frame forsupport of a vehicle, the frame having a forward end, a rearward end andopposite sides, a pair of rails extending longitudinally of thesuspension at opposite sides of the frame, and front and rear hangersdepending from each rail at locations intermediate the ends of theframe. The suspension includes a pair of forwardly-extending beams, oneextending forward from one of the front hangers and the other extendingforward from the other front hanger, each of said forwardly-extendingbeams having a pivotal connection with the respective front hanger andhaving a support for a forward axle, and a pair of rearwardly-extendingbeams, one extending rearward from one of the rear hangers and the otherextending rearward from the other rear hanger, each of therearwardly-extending beams having a pivotal connection with therespective rear hanger and having a support for a rearward axle. Each ofthe pivotal connections between one of the hangers and a respective beamcomprises a resilient bushing assembly. A forward pair of springs isinterposed between respective forwardly-extending beams and the frame,and a rearward pair of springs is interposed between respectiverearwardly-extending beams and the frame.

[0006] Another aspect of this invention is directed to a bushingassembly for a pivot connection between a vehicle frame andaxle-supporting beam of a vehicle suspension to permit pivoting of thebeam relative to the frame. The bushing assembly comprises an innermetal sleeve having a central longitudinal axis about which the beam isadapted to pivot, and a resilient annular bushing member of resilientmaterial surrounding the inner metal sleeve. The bushing member has aradial inner surface adjacent the inner metal sleeve and an oppositeradial outer surface. An outer metal sleeve surrounds the bushingmember, the outer metal sleeve having a radial inner surface adjacentthe bushing member and an opposite radial outer surface. The outersurface of the resilient bushing member is relieved in a radially inwarddirection toward said central longitudinal axis to facilitate deflectionof the bushing member in said radially inward direction.

[0007] In another aspect, a vehicle suspension of the present inventioncomprises a frame having opposite sides, and a pair of suspension beamsat opposite sides of the frame, each beam having first and second ends.Each beam is pivotally connected to the frame generally adjacent thefirst end of the beam. An axle support is provided toward the second endof each for supporting an axle on the beam. The support includes a pairof side seat assemblies on opposite sides of the beam. Each side seatassembly comprises first and second seats having opposingaxle-supporting surfaces, and a fastener for drawing the first andsecond seats toward one another to clamp the axle-supporting surfacesagainst the axle. A camshaft bracket and a brake chamber bracket aremounted on the axle support.

[0008] Another aspect of the present invention is directed to a vehiclesuspension system comprising a frame having opposite sides, and a pairof suspension beams at opposite sides of the frame each having a pivotalball joint connection at one end thereof with the frame and an axlesupport at the other end thereof.

[0009] In another embodiment, a vehicle suspension of the presentinvention comprises a frame having opposite sides, and a pair ofsuspension beams at opposite sides of the frame, each beam having firstand second ends. A pivotal connection is provided between each beam andthe frame generally adjacent the first end of the beam. The suspensionincludes an axle of generally rectangular cross section extendinggenerally transversely with respect to the frame from one side of theframe to the other, and an axle support on each of the beams toward thesecond end of the beam for supporting the axle on the beam. The axlesupport includes at least one side seat affixed to the beam at one sideof the beam and at least one U-bolt fastener defining an axle-receivingopening, the U-bolt fastener having legs extending through openings inthe side seat, and nuts threaded on the legs of the U-bolt fastener totighten the fastener and thereby clamp the axle in fixed positionagainst the side seat. The nuts are removable from the at least oneU-bolt fastener to permit removal of the axle from the beam.

[0010] In another embodiment, a vehicle suspension of the presentinvention comprises a frame having opposite sides and a pair of elongatesuspension beams at opposite sides of the frame. Each beam has oppositesides, opposite ends, a pivotal connection with the frame toward one endof the beam, and an axle support toward the other end thereof. The axlesupport comprises a pair of axle side seats secured to the beam andprojecting laterally outwardly from opposite sides of the beam. The sideseats have axle-supporting surfaces for supporting the axle at locationsoutboard of beam. A mechanism is provided for securing the axle in theoutboard axle side seats.

[0011] Other objects and features will in part apparent and in pointedout hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a perspective of a first embodiment of a vehiclesuspension in which the suspension beams are in a push-pull orientationand pivoted to equalizing levers;

[0013]FIG. 2 is a side elevation of FIG. 1;

[0014]FIG. 3 is a side elevation showing a pair of springs for urgingthe equalizing lever to a generally horizontal position;

[0015]FIG. 4 is an enlarged horizontal section taken in the plane of 4-4of FIG. 2;

[0016]FIG. 5 is a cross-sectional view showing an alternative bushingconnection between a suspension beam and one end of an equalizing lever;

[0017]FIG. 6 is a sectional view similar to FIG. 4 showing ball jointconnections between an equalizing lever and two suspension beams;

[0018]FIG. 7 is a perspective of one of the ball joints of FIG. 6;

[0019]FIG. 8 is a sectional view of an alternative ball for the balljoints of FIG. 6;

[0020]FIG. 9 is a sectional view similar to FIG. 6 showing eccentricball joint connections;

[0021]FIG. 10 is a perspective of one of the ball joints of FIG. 9;

[0022]FIG. 11 is a sectional view of the ball joint of FIG. 9;

[0023]FIG. 12 is an exploded view of the ball joint of FIG. 9;

[0024]FIG. 13 is a top perspective of an axle support on a suspensionbeam;

[0025]FIG. 14 is a top plan view of the axle support and beam of FIG.13;

[0026]FIGS. 15-18 are sectional views taken on in the planes of lines15-15, 16-16, 17-17 and 18-18, respectively, on FIG. 14;

[0027]FIG. 19 is a perspective view similar to FIG. 13 but without theaxle and showing certain parts exploded to illustrate details of theaxle support;

[0028]FIG. 20 is an enlarged perspective of a portion of FIG. 19 showingfeatures of the axle support;

[0029]FIG. 21 is a top perspective showing an alternative axle support;

[0030]FIG. 22 is a bottom perspective of the axle support of FIG. 21;

[0031]FIG. 23 is a another top perspective of the axle support of FIG.21, taken from a different vantage point;

[0032]FIG. 24 is another bottom perspective of the axle support of FIG.21, taken from a different vantage point;

[0033]FIG. 25 is a perspective view of the assembly of FIG. 21 turnedupside down and with the axle removed to better illustrate the axlesupport;

[0034]FIG. 26 is a schematic view showing the axle support area of thedesign of FIG. 21;

[0035]FIG. 27 is a schematic view showing the axle support area of aprior art design;

[0036]FIG. 28 is a perspective of another embodiment of the suspensionin which the equalizing levers are eliminated and in which thesuspension beams at each side of the frame are pivoted on hangers andconnected by a spacer bar for maintaining the distance between the pivotpoints fixed;

[0037]FIG. 29 is a side elevation of the suspension of FIG. 28;

[0038]FIG. 30 is an enlarged section taken in the plane of line 30-30 ofFIG. 29 showing bushing assemblies for pivotally connecting thesuspension beams to the hangers;

[0039]FIG. 31 is a perspective a bushing member of a bushing assembly ofFIG. 30;

[0040]FIG. 32 is a top plan view of the bushing member of FIG. 31;

[0041]FIG. 33 is an end elevation of the bushing member;

[0042]FIG. 34 is a sectional view taken in the plane of line 34—34 ofFIG. 33;

[0043]FIG. 35 is a sectional view taken in the plane of line 35—35 ofFIG. 32;

[0044]FIG. 36 is a view similar to FIG. 35 showing the bushing memberassembled with an outer sleeve;

[0045]FIG. 37 is a top perspective of an axle support for supporting anaxle of rectangular cross section on a suspension beam;

[0046]FIG. 38 is a side elevation of the axle support of FIG. 37;

[0047]FIG. 39 is a top plan of FIG. 37;

[0048]FIG. 40 is a right end view of the axle support of FIG. 37;

[0049]FIG. 41 is a sectional view taken in the plane of line 41-41 ofFIG. 39;

[0050]FIG. 42 is a bottom perspective of a suspension beam and axlesupport with a brake chamber bracket and camshaft bearing bracketmounted on the axle support;

[0051]FIG. 43 is a top perspective of the suspension beam and axlesupport of FIG. 42;

[0052]FIG. 44 is a top perspective of another embodiment of a suspensionbeam and axle support with a brake chamber bracket and camshaft bearingbracket mounted on the support; and

[0053]FIG. 45 is a bottom perspective of the suspension beam and axlesupport of FIG. 44.

[0054] Corresponding parts are designated by corresponding referencenumerals throughout the several views of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0055] Referring now to FIGS. 1-4 of the drawings, a vehicle suspensionof the present invention is designated in its entirety the referencenumeral 1. As shown, the suspension is a slider of the type which isaffixed to the frame of truck. However, it will be understood that thepresent invention has applications to vehicle suspensions generally.

[0056] The suspension comprises a frame 3 which includes a pair ofparallel rails 5 connected by cross members 7, and hangers 9 dependingfrom the rails 5 at opposite sides of the frame generally midway betweenthe ends of the rails. The frame has forward and rearward ends, theforward end being the left end as viewed in FIG. 1 and the rearward endbeing the opposite (right) end. In accordance with one aspect of thepresent invention, the frame further comprises a pair of levers 11,referred to as equalizers, one at one side of the frame 3 and the otherat the other side of the frame. Each lever 11 (comprising two parallelbars 11 a, 11 b in the embodiment shown in FIGS. 1-4) has a pivotconnection, generally designated 15, with a respective hanger 9 forswinging movement on a generally horizontal axis 16 intermediateopposite ends of the lever transverse to the frame. The frame alsoincludes a pair of suspension beams 17 extending forward from one end ofthe levers 11, and a pair of suspension beams 19 extending rearward fromthe other end of the levers. Each of the forward-extending beams 17 hasa pivot connection 23 with the respective lever forward of the leverpivot connection 15 and further supports a forward axle 27. Each of therearward-extending beams 19 has a pivot connection 29 with therespective lever 11 rearward of the lever pivot connection 15 andsupports a rearward axle 33. A forward pair of springs 35 (e.g., airbags) is interposed between respective forward-extending beams 17 andthe frame 3, and a rearward pair of springs 37 (e.g., air bags) isinterposed between respective rearward-extending beams 19 and the frame3. The forward and rearward beams 17, 19 carry axle supports, eachgenerally designated 41, for supporting the respective axles on thebeams.

[0057] The levers 11 function to permit the suspension beams 17, 19 tomove essentially independently of one another, so that the loading onthe wheels of the vehicle is maintained substantially uniform as thevehicle moves over bumps in the road and as the vehicle turns. Thesuspension provides good roll stability or stiffness, i.e., resistanceto rollover during cornering, and minimizes axle torque, especiallyduring travel over bumps, potholes and the like. For efficientoperation, the levers 11 are maintained in a generally horizontalposition by the resilient nature of the pivot connections 15, as will bedescribed, although other means may be used, e.g., coil compressionsprings 45 (FIG. 3), rubber springs, or linkages.

[0058] In the embodiment illustrated in FIGS. 1-4, each hanger 9comprises a pair of parallel generally triangular spaced apart metalplates 51 affixed (e.g., welded) to a respective rail 5 of the frame.The hanger plates 51 are reinforced along their sides by stiffeningflanges 53 and at their bottoms by reinforcing plates 55 welded thereto(see FIG. 4). The equalizing lever 11 at each side of the frame ispreferably disposed between the two hanger plates 51 of a respectivehanger adjacent the lower ends of the plates.

[0059] The pivot connection 15 between the equalizing lever 11 and thehanger 9 at each side of the frame is shown in FIG. 4 as comprising abushing assembly generally designated 59 having inner and outer sleeves61, 63 and a tubular bushing member 65 of resilient material (e.g.,rubber having a Shore A durometer preferably in the range of 65-75 andmore preferably about 70) between the sleeves, all three componentsbeing concentric with the pivot axis 16. The outer sleeve 63 is receivedin aligned holes in the two equalizer bars 11 a, 11 b and is immovablyaffixed to the bars, as by welding. The outer sleeve 63 is somewhatshorter (e.g., 0.062 in.) than the inner sleeve 61, for reasons whichwill become apparent. The resilient bushing member 65 has a press(frictional) fit with the inner and outer sleeves 61, 63 to preventrelative rotation between the inner surface of the bushing member andthe inner sleeve and between the outer surface of the bushing and theouter sleeve. The resiliency of the bushing material itself allowslimited relative rotational and angular movement between the inner andouter sleeves 61, 63, “angular” meaning movement of the axes of the twosleeves out of parallelism. A pivot bolt 71 extending through the innersleeve 61 and through aligned openings 73 in the hanger plates 51 andaligned openings 75 in the reinforcing plates 55 is held in place by anut 77 threaded up on the bolt. Conventional washers 79 are provided onthe bolt 71 between the hanger plates 51 and the head of the bolt andthe nut 73. Hardened 81 washers are disposed between the ends of thebushing assembly 59 and the reinforcing plates 55 of the hanger. Whenthe nut 77 is tightened on the pivot bolt 71, the hardened washers 81and inner sleeve 61 of the bushing assembly are clamped in fixed(non-rotatable) position. Since the outer sleeve 63 is shorter than theinner sleeve 61, it is free to rotate to the extent permitted by theflexing of the resilient bushing member 65. This rotation occurs as theequalizing lever 11 pivots on the pivot bolt 71 in response to up anddown movement of the suspension beams 17, 19 to equalize the forces onthe axles 27, 33 carried by the beams. The resilience of the bushingmember 65 urges the lever 11 back toward a neutral (horizontal)position.

[0060] It will be noted that the openings 73, 75 in the hanger plates 51and reinforcing plates 51, 55 are clearance openings substantiallylarger in diameter than the diameter of the pivot bolt 71. This allowsfor fore and aft adjustment of the equalizing lever 11 and associatedbeams 17, 19 to permit adjustment of the respective ends of the axlescarried by the beams to attain precise alignment of the axlestransversely of the vehicle. (When properly aligned, the front and rearaxles carried by the suspension beams should be parallel to one anotherand perpendicular to the longitudinal centerline of the trailer,typically extending through the kingpin of the vehicle.) After theposition of each lever 11 is adjusted to achieve proper axle alignment,the nuts 77 are tightened on the pivot bolts 71 to lock the equalizinglevers 11 in fixed position relative to respective hangers 9. Ifdesired, the pivot bolt washers 77 (which have a close clearance fitwith the pivot bolt) can also be welded to respective hanger plates 51to further insure that the equalizer remains in proper position tomaintain axle alignment.

[0061] The construction of the pivot connections 23, 29 between thelevers and the beams 17 is also shown in FIG. 4. As illustrated, eachsuch pivot connection 23, 29 comprises a bushing assembly generallydesignated 85 disposed between the two bars 11 a, 11 b of the equalizinglever 11 adjacent an end of the lever. The bushing assembly 85 comprisesconcentric inner and outer sleeves 87, 89 surrounding a cylindricresilient bushing member 91 having a press (frictional) fit with bothsleeves. In one embodiment, the bushing member is of rubber preferablyhaving a 65-75 Shore A durometer, and more preferably about a 70 Shore Adurometer. The outer sleeve 89 of the bushing assembly is affixed (e.g.,welded) to a respective beam 17, 19. The assembly 85 is held in place bya pivot bolt 95 extending through the inner sleeve 87 and aligned holesin the lever bars 11 a, 11 b, and a nut 99 threaded up on the boltagainst one of the bars. Hardened metal washers 101 are provided betweenthe ends of the inner sleeve 87 and the lever bars. When the nut 99 istightened, the inner sleeve 87 and washers 101 are clamped in fixed(non-rotating) position relative to the lever bars 11 a, 11 b. The outersleeve 89 is somewhat shorter than the inner sleeve 87 to provide gapsbetween the ends of the sleeve and the washers. The resilience of thebushing member 91 provides limited rotational and angular movementbetween the inner and outer sleeves 87, 89 of the bushing assembly topermit limited pivotal and angular movement between the respective beam17, 19 and the lever 11. Angular movement of the outer sleeve 89relative to the inner sleeve 87 of the bushing (caused by jackknifeforces exerted on the beam) is limited by contact between the ends ofthe outer sleeve 89 and the hardened washers 101. The ends of thebushing member 91 are tapered to prevent undue rubbing of the bushingmember against the washers 101.

[0062] It will be observed from the foregoing that the suspension beams17, 19 are arranged in a push-pull orientation, that is, the forwardbeams are pushed forward and the rearward beams are pulled forward asthe vehicle moves along the road. This arrangement eliminates the “dockwalk” problem suffered by many conventional air-ride suspensions.Further, the use of the equalizing levers 11 equalizes the load betweenthe wheels of the vehicle, thereby reducing axle torque while providinggood roll stability. The pivot connections 23, 29 between the suspensionbeams and the hangers 9 reduce the number of parts used in conventionaldesigns, thus allowing for a reduction in weight of the suspension andreducing wear.

[0063] While the suspension of the present invention is applicable toair-ride suspensions, it will be understood that any type of springelement may be used in lieu of an air bag. For example, the air springsare replaced by rubber springs of the type commercially available fromTimbren Industries Inc. of Niagara Falls, N.Y., Model Aeon® 570 RubberSpring support. Also, it will be understood that an equalizing lever ofthe present invention could comprise a single bar or the like pivotallymounted to a hanger. Similarly, the hangers, beams and other componentsof the suspension 1 could take other forms.

[0064]FIG. 5 shows an alternative bushing assembly 105 for use in aconnection between a flange 106 and a beam or between a lever (notshown) and a beam 17, 19. In this embodiment, interlocking ribs 107, 109are formed on the inner surface of the outer sleeve 111 and on the outersurface of the bushing member 113 to prevent axial slippage between thetwo parts. The friction lock provided by these ribs 107, 109 should besufficient to withstand the maximum lateral loads (e.g., 8000 lbs)applied to the axle during cornering of the vehicle. The ribs 107 on theouter sleeve 111 can be formed by machining the sleeve, or by rollforming. Further, the interference fit between the bushing member 113and the outer sleeve 111 can be provided by means other thaninterlocking ribs.

[0065]FIGS. 6-8 illustrate a third embodiment of a pivot connection,generally designated 121, between a lever 11 and a beam 17, 19. In thisembodiment, the pivot connection 121 comprises a ball joint designatedin its entirety by the reference numeral 125. The ball joint comprises ahollow open-ended housing, and more particularly a cylindrical sleeve127, e.g. a steel sleeve, extending transversely of the beam 17, 19 atits pivot end, secured thereto as by welding at 129. Inserted in thesleeve are two annular bushings 131, which may be made of powdered metal(sintered). Each bushing 131 has a part-spherical cavity such asindicated at 135 and an opening 137 in the outside thereof extendingfrom its outside to the cavity. The bushings 131 are fitted tightly inthe sleeve 127 with their inner sides engaging one another, defining apart-spherical ball seat. A ball 141, made of steel, for example, isrotatably seated in the seat (before the bushings are inserted in thesleeve). The ball 141 has two aligned tubular projections eachdesignated 143 at opposite sides thereof which extend radially outwardto some extent through the openings 137 in the bushings 131. A bore 145through these projections, which may be termed “trunnions”, and throughthe ball 141 define a transverse hole for a bolt 151. The bushings 131,135 are held in the sleeve 127 by C-clips 155 snapped into internalannular grooves in the sleeve. In the ball joint 125, the bushings 131,the ball 141, and the tubular projections or trunnions 143 are coaxialwith the sleeve 127, the axis thereof (indicated at A-A in FIG. 6) beingdiametrical with respect to the ball seat and the ball 141, andextending centrally through the hole 145. The pivot bolt 151 and a nut161 thereon hold the ball joint in position with the ends of thetrunnions 143 clamped immovably against respective bars 11 a, 11 b ofthe equalizing lever. The ball joints 125 allow relative pivotalmovement between the beams 17, 19 and the equalizing lever 11, both in avertical plane and laterally with respect to this plane (to a limitedextent).

[0066]FIG. 8 shows an alternative design where the ball 165 of the balljoint is hollow, as indicated at 167. In this embodiment, the center ofthe hollow 167 is preferably aligned with the axis A-A of the tubularprojections 169.

[0067]FIGS. 9-12 illustrate a modification of the ball joint, designated125 a in its entirety, having parts generally corresponding to those ofball joint 125 and designated by the same reference numerals as used forball joint 125 with the subscript a (e.g. sleeve 127 a). Themodification 125 a differs from 125 primarily in that the tubularprojections or trunnions 143 a (143 in ball joint 125) are on an axisAa-Aa offset in relation to the diameter A-A of the ball shown in FIG.11, and in that is formed with flats 175 (FIG. 10) on each of thetubular projections or trunnions 143 a for application of a wrench forturning the ball 141 a relative to the ball seat formed by the bushings131 a. The bolt hole 145 a in the ball 141 a and trunnions 143 a is onaxis A-A, which is offset (eccentric) with respect to the center line ofthe trunnions (which is line Aa-Aa as shown in FIG. 11. The arrangement,with the ball 141 a thus mounted eccentrically in the seat to the extentindicated at E in FIG. 11, allows for fore and aft adjustment of thebeam 17, 19 on which the ball joint is mounted for fore and aftadjustment of the respective end of the axle carried by the beam toattain precise alignment of the axle transversely of the vehicle.

[0068] Referring to FIGS. 13-20, each axle support 41 comprises a pairof side seats each generally designated 201 on opposite sides of arespective beam 23, 29 intermediate the ends of the beam. In oneembodiment, the side seats 201 are integral steel castings each having agenerally vertical leg 205 affixed (e.g., welded) to a respective sidewall 207 of the beam, and a generally horizontal leg 209 having anoutboard section 211 extending laterally outboard of the beam and aninboard section 213 extending laterally inboard of the beam, the inneredges of the two inboard sections being relatively closely spaced overthe top wall 217 of the beam. The generally horizontal leg 209 of eachside seat 201 has an axle-supporting surface 221, preferably contoured(e.g., rounded) to match the contour of the axle 27, 33. The axle 27, 33is immovably held on these axle-supporting surfaces 221 by suitablefasteners, such as a pair of U-bolts 241 having threaded ends whichextend down through holes 243 in the outboard sections 211 of the sideseats, and nuts 245 tightened up on the U-bolts. Washers 247 areprovided between the nuts and the undersides of the castings. The axleis thus supported by these side seats 201 at locations outboard of thebeam on opposite sides of the beam, thereby reducing the bendingstresses on the axle compared to prior designs where the axle issupported more inboard with respect to the beam. Significantly, the axleis not welded to the side seats 201, at least in the embodiment shown inFIGS. 13-20, thereby avoiding stress risers in the axle at theselocations. The U-bolts 241 may be of the type which can be tightened andloosened, or lockbolts which, once tightened, remain permanentlysecured. Suitable lockbolts are commercially available from HuckInternational Inc. of Waco Tx. under the trade mark “U-Spin”. Othertypes of U-bolts or mechanical fasteners may be used.

[0069] Referring again to FIGS. 13-20, the axle support 41 preferablyfurther comprises a center axle seat 251 bridging the two side seats 201generally between opposite sides 207 of the beam. In one embodiment (seeFIGS. 19 and 20), the center seat 251 comprises a one-piece memberformed from metal plate having a pair of end sections 251 a connected bya center section 251 b of reduced width, thereby providing fourshoulders 255 at the corners of the member, the shoulders being receivedin notches 257 in the side seats. The center seat 251 has an axlesupporting surface 261, also contoured to match the contour of the axle.By way of example, and not limitation, the center seat may be a stampedsteel plate having a thickness of about 0.31 in. The center seat sitsdown in recesses 265 formed in the inboard sections 213 of the sideseats 201 so that the axle-supporting surface 261 of the center seat isflush with the axle-supporting surfaces of the 211 of the side seats, asshown best in FIG. 18. The center seat 251 is preferably welded to theinboard sections 213 of the side seats 201, as indicated in FIG. 13.

[0070]FIGS. 18-20 illustrate the steps involved in assembling the centerand side seats 209, 251. FIG. 20 shows the center seat 251 in placeprior to installation of the axle, the shoulders 255 of the center seatbeing received in the notches 257 in the side seats 201. Afterinstalling and tightening the U-bolts 241 (FIG. 18), the axle-supportingsurface 261 of the center seat should have a curvature and be at a levelwhich closely coincides with the curvature and level of theaxle-supporting surfaces 221 of the side seats 201. To provideadditional resistance against rotation of the axle 27, 33 relative tothe beam 25, 29, the axle is preferably rigidly affixed to the centerseat 251, as by a suitable adhesive, such as an anaerobic adhesive madeby Locktite Corporation providing a shear strength of 4,000 psi. The useof adhesive is advantageous over welding, for example, because it avoidsstress risers in the axle, thereby allowing the axle to be made oflighter (e.g., thinner wall) tubing.

[0071] In the embodiment of FIGS. 13-20, the side and center seats 201,251 combine to support the axle over a greater length of the axle(compared to prior art designs), thereby reducing axle stress. However,it is contemplated that the side seats 201 may be used without thecenter seat 251. Further, the side seats 201 may have configurationsother than as shown in the drawings. For example, one or both of theinboard sections 213 of the side seats could be eliminated. Also, theoutboard section 211 of one of the seats 201 could be eliminated.Further, the axle can be adhesively secured to the axle-supportingsurfaces 221 of the side seats 201, regardless of the presence of acenter seat 251.

[0072] While the axle supports 41 described above support the axles 27,33 above the beam 17, 19, the same supports 41 can be used to supportthe axles under the beam in an underslung fashion, as will be understoodby those skilled in this field.

[0073]FIGS. 21-25 illustrate an alternative axle support, generallydesignated 301, supporting an axle 27, 33 below the bottom wall 281 of asuspension beam 17, 19. The support 301 is generally similar to axlesupport 41 in that it comprises a pair of side seats, each designated305 and each having axle-supporting surfaces 307 contoured to match theshape of the axle. The side seats 305 extend laterally outboard of thebeam on opposite sides of the beam. U-bolts 309 or other mechanicalfasteners clamp the axle in place. The support 301 also has a centerseat, generally designated 311, but of different construction than thecenter seat 251 of axle support 41. In this embodiment, the center seat311 comprises two inboard seat members 313 formed (in one embodiment) byintegral extensions of the side seats 305, similar to two inboard sideseat sections 213 of axle support 41, but without the recesses 265. Theinboard seat members 313 have axle-supporting surfaces 315 (FIG. 25)contoured to match the shape of the axle. In one embodiment, theaxle-supporting surfaces 307, 315 of a side seat 305 and its adjacentinboard seat member 313 combine to provide a continuous uninterruptedarea for supporting the axle, as shown best in FIG. 25. Each center seatmember 313 is preferably formed as an integral part of a respective sideseat member 305, but it will be understood that they could be formed asseparate parts, with the center seat members being attached to the beam,for example. Also, the center seat members 313 could be formed as asingle one-piece casting, for example. Regardless of how the center seatmembers 313 are constructed, it is preferable that the axle be welded tothe center seat members, as indicated at 321 in the drawings (e.g.,FIGS. 22 and 23), to assist in holding the axle against rotation. Thestress risers in the axle caused by these welds are minimized because ofthe location of the welds generally inboard of the sides of the beam andbetween the two U-bolts 309.

[0074] Axle support 301 can be used to support an axle above asuspension beam as well as below the beam.

[0075] Like axle support 41, axle support 301 is advantageous forvarious reasons. For example, compared to prior axle supports, theextension of the area of axle support to locations outboard of the beam,and even outboard of the U-bolts, increases the area of axle support anddecreases the bending stresses on the axle. This is best illustrated bycomparing FIG. 26, schematically representing axle support 301, and FIG.27 schematically representing a conventional axle support, generallydesignated 331. The areas providing axle support are shaded in bothFigures. It is apparent that the area provided by support 301 issubstantially greater, since the support extends outboard of the beamand thus has a relatively large overall dimension D1 in a directiontaken transverse to the centerline of the vehicle. In contrast, theprior art support 301 provides support inboard of the beam only, and hasan overall transverse dimension D2 less than D1. (By way of example, D1may be in the range of 10-12 in., whereas D2 is typically in the rangeof 5-8 in.) As a result, the bending stresses on the axle are reducedsignificantly when support 301 is used, which enables the axle to bemade of lighter construction (e.g., reduced wall thickness).

[0076]FIGS. 28-30 illustrate another embodiment of the suspension,generally indicated at 351, in which the forward suspension beams 353and rearward suspension beams 355 are connected to forward and rearwardhangers designated 357 and 359, respectively, at each side of the frame.As shown in FIG. 30, the forward hanger 357 comprises a verticallyoriented channel-shaped hanger member having a pair of generallyparallel side walls 365 and a connecting wall 367 joining the side wallsat the rear edges of the side walls. The rearward hanger 359 comprises asimilar vertically oriented channel-shaped hanger member having a pairof generally parallel side walls 371 and a connecting wall 373 joiningthe side walls at the front edges of the side walls, the connectingwalls 367, 373 of the two hangers preferably being spaced from oneanother. Each beam 353, 355 has a pivot connection 375 with a respectivehanger member. This connection 375 comprises a bushing assembly,generally designated 379, a pivot bolt 381 passing through the bushingassembly 379 and through horizontal slots 385 in the side walls 365, 371of respective hangers, a first pair of hardened wear washers 387 on thebolt 381 between the ends of the bushing assembly 379 and the side wallsof the hangers, and a second pair of washers 391 on the bolts betweenthe heads of the bolts and the side walls of the hangers. The slots 385in the side walls of the hangers 357, 359 permit the position of eachbeam relative to its respective hanger to be adjusted inforward-to-rearward direction to insure that the axle clamped to thebeam is perpendicular to the longitudinal centerline of the frame andvehicle. Once adjusted, the position of the beam 353, 355 is fixed bytightening a nut 395 on the bolt. The distance D between the pivotconnections 375 of the forward and rearward beams to their respectivehangers at each side of the frame is maintained fixed by a pair ofspacer bars 399 having holes 401 therein for receiving the two bolts381. The spacing D between the bolts 381 at one side of the frame isabout equal to the spacing D between the bolts at the opposite side ofthe frame, so that the axles are maintained parallel.

[0077] Referring to FIGS. 30-36, the bushing assembly 379 comprises aninner metal sleeve 405 having a central longitudinal axis 407 aboutwhich the beam 353, 355 is adapted to pivot, and a cylindric bushingmember 411 of resilient material (e.g., molded rubber) surrounding theinner metal sleeve 405 and having a press (friction) fit thereon. Thebushing member 411 has a radial inner surface 413 adjacent the innermetal sleeve 405 and an opposite radial outer surface 415 (FIG. 34). Thebushing member 411 is press fit inside an outer metal sleeve 417 whichsurrounds the bushing member. The outer metal sleeve 417 has a radialinner surface 421 adjacent the bushing member 411 and an opposite radialouter surface 423 (FIG. 36). As shown in FIGS. 31-36, which illustratethe bushing member in its installed orientation on a vehicle, one ormore regions of the outer surface 415 of the resilient bushing member411 are relieved in a radially inward, generally vertical direction.That is, the vertical radial dimension of the bushing member is reducedin these regions to facilitate compression of the bushing member in thevertical direction (and thus vertical movement of the beam 353, 355relative to its respective hanger 357, 359). The bushing member 411 isnot substantially relieved in the horizontal direction, therebymaintaining the stiffness of the bushing member in a direction extendinggenerally longitudinally with respect to the vehicle. In the embodimentshown, the outer surface of the bushing member 411 has an unrelievedcylindric region 431 between opposite ends of the bushing member, and apair of relieved regions 433 formed by generally wedge-shaped recesseson opposite sides of the unrelieved region 431 toward opposite ends ofthe bushing member. This end-relief configuration facilitates angularrocking movement of the inner sleeve 405 relative to the outer sleeve asis apparent from FIG. 36, “angular” movement being movement of the twosleeves out of parallel to a position in which the axes of the twosleeves are skewed relative to one another. In one preferred form (FIG.36), the relieved regions 433 have combined axial lengths L1 greaterthan the axial length L2 of the unrelieved region 431, and each relievedregion curves generally radially inward and axially toward a respectiveend of the bushing member 411. The bushing member 411 is preferablyconfigured so that when it is pressed in place between the inner andouter sleeves 405, 417, the ends of the bushing member are generallyflush (co-planar) with the ends of the inner sleeve 405. By way ofexample, referring to FIG. 34, the bushing member 411 may be configuredto have ends tapered at an angle e (about 30 degrees in one embodiment)prior to assembly with the outer sleeve 417. During assembly, e.g., asthe member 411 and outer sleeve 417 are press fit together, the member411 deforms to assume a final configuration wherein the ends of thebushing member are generally flush with the inner sleeve. As inpreviously described embodiments, the outer sleeve 417 is somewhatshorter than the inner sleeve 405 so that when the pivot bolt 381 istightened, the inner sleeve is clamped fixedly in place while the outersleeve is allowed to rotate to a limited extent (as permitted by theflexibility of the bushing member 411) to accommodate pivoting of thebeam 353, 355. Angular movement of the outer sleeve (and beam) relativeto the inner sleeve (and hanger) is restricted by engagement of the endsof the outer sleeve 417 with the hardened washers 387.

[0078] By way of example, but not limitation, the unrelieved region 431of the installed bushing member 411 shown in FIG. 36, may have an axiallength L2 of about 2.0 in., and the combined axial lengths L1 of therelieved regions 433 may be about 3.0 in., providing an overall bushingmember length of about 5.0 in., which generally corresponds to thelength of the inner metal sleeve 405. Further, the cylindric unrelievedregion 431 of the bushing member 411 may have an outside diameter ofabout 4.375 in. and an inside diameter of about 2.0 in. The relievedregions 433 may have an outside diameter OD at the ends of the bushingmember of about 3.75 in., an inside diameter ID of about 2.0 in., and aradius of curvature of about 1.0 in (see FIG. 36). The outer sleeve 417may have an overall length about 0.250 in. less than the inner sleeve405.

[0079] The design of bushing assembly 379 is advantageous in that thevertical radial relief of the bushing member 411 enables greaterdeflection of the bushing member under a given vertical load whilemaintaining bushing stiffness under generally horizontal loads (i.e.,loads in the generally longitudinal direction with respect to thevehicle). This design reduces the need for axle realignment and yetprovides for good roll stiffness of the vehicle. It will be understoodthat the specific relieved configuration of the bushing member 411 canchange without departing from the scope of this invention.

[0080]FIGS. 37-41 illustrate an axle support of the present invention,generally designated 451, for use with an axle 453 of generallyrectangular (e.g., square) cross section. The axle 453 may be solid ortubular and has four generally flat sides 455 and four rounded corners457. The support 451 includes at least one side seat 461, and preferablytwo side seats 461 on opposite sides of the beam 17, 19. These seats 461are similar to the side seats 305 of axle support 301 except that eachseat 461 has an axle-supporting surface 465 contoured to fit the contourof the rectangular axle 453. In one embodiment, the axle-supportingsurface 465 of each seat 461 extends on three sides of the axle,corresponding to one side 455 and two adjacent corners 457 of the axle(see FIGS. 38 and 41). The axle 453 is supported on each side seat 461by a U-bolt fastener 467 having legs extending up through openings 471in the generally horizontal legs 475 of the side seats 461, and nuts 481threaded on the legs of the U-bolt fastener to tighten the fastener andthereby clamp the axle against rotational and axial movement relative tothe beam. No welding of the axle to the seat 461 is necessary, providedthe axle-supporting surface 465 extends around at least two corners 457of the axle when the axle is clamped tight against the seat. As a resultof this construction, the axle may be readily removed from the beamsimply by removing the U-bolt fasteners 467. The side seats 461 aresuitably reinforced, as by gussets and reinforcing ribs.

[0081] In the embodiment just described, the axle support 451 does nothave a center seat, but it will be understood that a center seat can beprovided, if desired. Also, as with the prior embodiments, it will beunderstood that the axle support 451 can be used for supporting an axleabove or below the suspension beam.

[0082]FIGS. 42 and 43 illustrate another axle support, generallydesignated 501, for supporting a rectangular axle (not shown) on asuspension beam 503. The support 501 includes at least one side seatassembly 505 on one side of the beam, and preferably two side seatassemblies 505 on opposite sides of the beam, two such assemblies beingshown in FIGS. 42 and 43. Each seat assembly 505 includes first andsecond opposing seats designated 509 and 511, respectively, the firstseat 509 being a fixed upper seat in one embodiment and the second seat511 being a lower movable seat. The upper fixed seat 509 has a generallyvertical leg 515 affixed (as by bolted connections or by welding) to arespective side of the suspension beam 503, and a generally horizontalleg 517 extending laterally out from the beam. The lower movable seat517 is spaced below the generally horizontal leg 517 of the upper seat509. The seats 509, 511 have opposing axle-supporting surfaces 521, eachof which is preferably contoured to match the shape of the axle. Forexample, in one embodiment each axle-supporting surface 521 is contouredto extend on one side of a rectangular axle and around two adjacentcorners of the axle. Fasteners 525 (e.g., nut and bolt fasteners) areused to draw the upper and lower seats 509, 511 toward one another toclamp a respective axle therebetween against the axle-supportingsurfaces 521 of the two seats. The fasteners can be of the type whichcan be tightened or loosened, or lock fasteners of the type which, oncetightened, remain permanently secured.

[0083] It will be understood that the axle support 501 can also be usedto support an axle above a suspension beam, in which case the movableseat 511 will be above the fixed seat 509. Further, the axle support 501may be used to support an axle having any cross-sectional shape, so longas the axle-supporting surfaces 521 on opposing seats are configured tomatch the contour of the axle.

[0084] Again referring to FIGS. 42 and 43, a camshaft bearing bracket531 for mounting the camshaft bearing (not shown) is affixed, as bywelding, to a fixed upper seat 509 of one of the side seat assemblies505. In one embodiment, the bracket 531 is generally C-shaped and issecured to a generally downwardly facing surface 533 on the upper seat509 adjacent the axle-supporting surface 521. Further, a separate brakechamber bracket 537 is secured to the movable lower seats 511 of the twoside seat assemblies 505. In the particular embodiment shown, the brakechamber bracket 537 is generally L-shaped, having generally vertical andhorizontal legs. The bracket 537 is secured in place by the fasteners525 and is used to mount the brake chamber (not shown) in a position inwhich the push rod of the brake chamber, when extended by actuation ofthe brake pedal, moves to rotate the camshaft in the camshaft bearing.Such rotation causes a conventional S-cam on the camshaft to push thebrake shoes against the drum of the wheel to brake the wheel, as will beunderstood by those in this field. In conventional designs, the brakechamber bracket 537 and camshaft bearing bracket 531 are welded directlyto the axle, causing stress risers in the axle. The present designeliminates the need to weld these brackets to the axle.

[0085]FIGS. 44 and 45 illustrate another axle support, generallydesignated 601, for supporting an axle 603, shown in this embodiment asrectangular, although it will be understood that the axle could haveother shapes (e.g., circular). The support 601 is elongate and extendsthrough the side walls of a suspension beam 607 in a position whereinthe support 601 projects laterally outward from opposite sides of thebeam. The support 601 comprises upper and lower channel members 609, 611which surround the axle 603 and hold it in fixed position. This may beaccomplished, in one embodiment, by welding a first of the two channelmembers (e.g., 609) to the beam 607, positioning the axle 603 in thefirst channel member, positioning the second channel member (e.g., 611)on the axle, drawing the two channel member together to clamp the axletherebetween, welding the two channel members 609, 611 together alongtheir adjacent edges, as indicated at 615, and welding the secondchannel member to the beam 607. This procedure has the benefit ofminimizing any direct welds to the axle. Alternatively, the axle can bewelded to one or both channel members 609, 611.

[0086] As shown in FIGS. 44 and 45, a brake chamber bracket 621 is heldby a pair of arms 623 affixed to the lower channel member 611 at oneside of the beam, and a camshaft bearing bracket 625 is affixed to theupper and lower channel members 609, 611 on the opposite side of thebeam. Similar to axle support 501, this arrangement avoids weldingeither bracket 621, 625 to the axle.

[0087] The axle support designs described above have several advantages,including the elimination of welding of certain parts to the axles, andthe reduction in bending stresses on the axles.

[0088] When introducing elements of the present invention or thepreferred embodiment(s) thereof, the articles “a”, “an”, “the” and“said” are intended to mean that there are one or more of the elements.The terms “comprising”, “including” and “having” are intended to beinclusive and mean that there may be additional elements other than thelisted elements.

[0089] In view of the above, it will be seen that the several objects ofthe invention are achieved and other advantageous results attained.

[0090] As various changes could be made in the above constructionswithout departing from the scope of the invention, it is intended thatall matter contained in the above description or shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense.

What is claimed is:
 1. A vehicle suspension comprising: a frame forsupport of a vehicle, said frame having a forward end, a rearward endand sides; a pair of levers carried by the frame intermediate the endsof the frame, one at one side and the other at the other side of theframe, each lever being pivotally mounted with respect to the frame forswinging movement on an axis intermediate opposite ends of the levertransverse to the frame; a pair of beams, one extending forward from oneof the levers and the other extending forward from the other lever, eachof said forwardly-extending beams having a pivotal connection with therespective lever forward of the lever axis and having a support for aforward axle; a pair of beams, one extending rearward from one of thelevers and the other extending rearward from the other lever, each ofsaid rearwardly-extending beams having a pivotal connection with therespective lever rearward of the lever axis and having a support for arearward axle; a forward pair of springs each interposed between arespective forwardly-extending beam and the frame; and a rearward pairof springs each interposed between a respective rearwardly-extendingbeam and the frame.
 2. A suspension as set forth in claim 1 wherein theaxis of the one lever is generally aligned with the axis of the otherlever transversely of the frame.
 3. A suspension as set forth in claim 2wherein the pivotal connection of each beam with the respective leverconnects the beam and lever for pivotal movement of one relative to theother on an axis transverse to the frame.
 4. A suspension as set forthin claim 1 having a pair of hangers, one extending down from the frameat one side and the other extending down from the frame at the otherside, each lever being pivotally mounted on a respective hanger.
 5. Asuspension as set forth in claim 4 wherein each lever is a double-sidedlever having sides adjacent opposite sides of the respective hanger andwherein the pivotal connection of each beam with the respective lever isbetween the sides of the lever with the axis of the pivotal connectiontransverse to the hanger.
 6. A suspension as set forth in claim 1wherein said springs are pneumatic springs.
 7. A suspension as set forthin claim 1 wherein said springs are leaf springs.
 8. A suspension as setforth in claim 1 wherein said springs are rubber springs.
 9. A vehiclesuspension comprising: a frame for support of a vehicle, said framehaving a forward end, a rearward end and opposite sides, a pair of railsextending longitudinally of the suspension at opposite sides of theframe, and front and rear hangers depending from each rail at locationsintermediate the ends of the frame; a pair of forwardly-extending beams,one extending forward from one of the front hangers and the otherextending forward from the other front hanger, each of saidforwardly-extending beams having a pivotal connection with therespective front hanger forward and having a support for a forward axle;a pair of rearwardly-extending beams, one extending rearward from one ofthe rear hangers and the other extending rearward from the other rearhanger, each of said rearwardly-extending beams having a pivotalconnection with the respective rear hanger and having a support for arearward axle; each of said pivotal connections between one of saidhangers and a respective beam comprising a resilient bushing assembly; aforward pair of springs each interposed between a respectiveforwardly-extending beam and the frame; and a rearward pair of springseach interposed between a respective rearwardly-extending beam and theframe.
 10. A suspension as set forth in claim 9 wherein said bushingassembly comprises an inner metal sleeve having a central longitudinalaxis about which said beam is adapted to pivot, a resilient annularbushing member of resilient material surrounding said inner metalsleeve, said bushing member having a radial inner surface adjacent saidinner metal sleeve and a radial outer surface, an outer metal sleevesurrounding said bushing member, said outer metal sleeve having a radialinner surface adjacent said bushing member and a radial outer surface,the outer surface of said resilient bushing member being relieved in aradially inward direction toward said central longitudinal axis tofacilitate deflection of the bushing member in said radially inwarddirection.
 11. A suspension as set forth in claim 10 wherein the outersurface of the bushing member is relieved radially inward at locationsadjacent ends of the bushing member to facilitate rocking movement ofthe inner sleeve relative to the outer sleeve.
 12. A suspension as setforth in claim 11 wherein the outer surface of the bushing member has anunrelieved axially-extending region between opposite ends of the bushingmember, and relieved regions on opposite sides of the unrelieved region.13. A suspension as set forth in claim 12 wherein said relieved regionshave combined axial lengths greater than the axial length of theunrelieved region.
 14. A suspension as set forth in claim 13 whereineach relieved region curves generally radially inward and axially towarda respective end of the bushing member.
 15. A suspension as set forth inclaim 13 wherein said bushing member has a press fit on said innersleeve and said outer sleeve has a press fit on said bushing member, andwherein the bushing member has opposite ends which are generallycoplanar with respective ends of the inner sleeve.
 16. A bushingassembly for a pivot connection between a vehicle frame andaxle-supporting beam of a vehicle suspension to permit pivoting of thebeam relative to the frame, said bushing assembly comprising an innermetal sleeve having a central longitudinal axis about which said beam isadapted to pivot, a resilient annular bushing member of resilientmaterial surrounding said inner metal sleeve, said bushing member havinga radial inner surface adjacent said inner metal sleeve and a radialouter surface, an outer metal sleeve surrounding said bushing member,said outer metal sleeve having a radial inner surface adjacent saidbushing member and a radial outer surface, the outer surface of saidresilient bushing member being relieved in a radially inward directiontoward said central longitudinal axis to facilitate deflection of thebushing member in said radially inward direction.
 17. A bushing assemblyas set forth in claim 16 wherein the outer surface of the bushing memberis relieved radially inward at locations adjacent ends of the bushingmember to facilitate angular movement of the inner sleeve relative tothe outer sleeve to a position in which the axes of the two sleeves areskewed relative to one another.
 18. A bushing assembly as set forth inclaim 17 wherein the outer surface of the bushing member has anunrelieved axially-extending region between opposite ends of the bushingmember, and relieved regions on opposite sides of the unrelieved region.19. A bushing assembly as set forth in claim 18 wherein said relievedregions have combined axial lengths greater than the axial length of theunrelieved region.
 20. A bushing assembly as set forth in claim 18wherein each relieved region curves generally radially inward andaxially toward a respective end of the bushing member.
 21. A bushingassembly as set forth in claim 20 wherein said bushing member has apress fit on said inner sleeve and said outer sleeve has a press fit onsaid bushing member, and wherein the bushing member has opposite endswhich are generally coplanar with respective ends of the inner sleeve.22. A bushing assembly as set forth in claim 20 wherein each relievedregion curves generally radially inward and axially toward a respectiveend of the bushing member.
 23. A vehicle suspension comprising: a framehaving opposite sides; a pair of suspension beams at opposite sides ofthe frame, each beam having first and second ends; a pivotal connectionbetween each beam and the frame generally adjacent the first end of thebeam; an axle support on each beam toward the second end of the beam forsupporting an axle on the beam, said axle support including a pair ofside seat assemblies on opposite sides of the beam, each side seatassembly including a first seat and a second seat having opposingaxle-supporting surfaces, and a fastener for drawing the first andsecond seats toward one another to clamp the axle-supporting surfacesagainst the axle; a camshaft bracket mounted on the axle support; and abrake chamber bracket mounted on the axle support.
 24. A suspension asset forth in claim 23 wherein said first seat of each side seat assemblyis affixed to the beam and the second seat of each side seat assembly ismovable relative to the first seat.
 25. A suspension as set forth inclaim 24 wherein said camshaft bracket is mounted on a first seat of oneof the side seat assemblies.
 26. A suspension as set forth in claim 25wherein brake chamber bracket is mounted on the second seats of the sideseat assemblies.
 27. A suspension as set forth in claim 24 wherein saidfastener comprises a pair of bolts extending through openings in thefirst and second seats, and nuts threaded on the bolts.
 28. A vehiclesuspension comprising: a frame having opposite sides; a pair ofsuspension beams at opposite sides of the frame each having a pivotalconnection adjacent one end thereof with the frame and an axle supporttoward an opposite end thereof, said pivotal connection comprising aball joint.
 29. A suspension as set forth in claim 28 wherein said balljoint comprises: an open-ended housing extending transversely of thebeam at said one end thereof, two bushings in the housing defining apart-spherical ball seat, a ball rotatably seated in said seat havingaligned tubular projections at opposite sides extending radially outwardthrough the bushings, said projections and ball defining a transversehole for a bolt adjacent said one end of the beam.
 30. A suspensionsystem as set forth in claim 29 wherein said ball is rotatable in theseat on an axis extending diametrically with respect to the ball.
 31. Asuspension system as set forth in claim 29 wherein said ball isrotatable in the seat on an axis offset from a diameter of the ball andis formed at least on one of the projections for application of awrench.
 32. A vehicle suspension comprising: a frame having oppositesides; a pair of suspension beams at opposite sides of the frame, eachbeam having first and second ends; a pivotal connection between eachbeam and the frame generally adjacent the first end of the beam; an axleof generally rectangular cross section extending generally transverselywith respect to the frame from one side of the frame to the other; andan axle support on each of said beams toward the second end of the beamfor supporting said axle on the beam, said axle support including atleast one side seat affixed to the beam at one side of the beam and atleast one U-bolt fastener defining an axle-receiving opening, saidU-bolt fastener having legs extending through openings in said sideseat, and nuts threaded on the legs of the U-bolt fastener to tightenthe fastener and thereby clamp the axle in fixed position against saidside seat, said nuts being removable from said at least one U-boltfastener to permit removal of the axle from the beam.
 33. A suspensionas set forth in claim 32 wherein said axle support comprises a pair ofsaid side seats affixed to the beam at opposite sides of the beam, and apair of said U-bolt fasteners.
 34. A suspension as set forth in claim 32wherein said side seat is secured to a side wall of the beam and has anaxle-supporting surface contoured to fit the contour of the axle onthree sides of the axle.
 35. A vehicle suspension comprising: a framehaving opposite sides; a pair of elongate suspension beams at oppositesides of the frame, each beam having opposite sides, opposite ends, apivotal connection with the frame toward one end of the beam, and anaxle support toward the other end thereof, said axle support comprisinga pair of axle side seats secured to the beam and projecting laterallyoutwardly from said opposite sides of the beam, said side seats havingaxle-supporting surfaces for supporting the axle at locations outboardof beam, and a mechanism for securing the axle in said outboard axleside seats.
 36. A vehicle suspension as set forth in claim 35 whereinsaid mechanism comprises a pair of U-bolts which, when tightened, clampthe axle against said axle-supporting surfaces.
 37. A vehicle suspensionas set forth in claim 36 wherein said U-bolts are located outboard ofopposite sides of the beam, and wherein said axle-supporting surfacesextend laterally outwardly with respect to the beam beyond respectiveU-bolts.
 38. A vehicle suspension as set forth in claim 35 wherein theaxle is not welded to said axle side seats.
 39. A vehicle suspension asset forth in claim 35 wherein said axle support further comprises anaxle center seat between the axle side seats, said center seat having anaxle-supporting surface inboard of the sides of the beam.
 40. A vehiclesuspension as set forth in claim 39 wherein the axle side seats haveinboard sections extending inboard of the beam, said wherein center seatis welded to said inboard sections.
 41. A vehicle suspension as setforth in claim 39 wherein said axle is affixed to said axle center seatat a location inboard of the axle side seats.
 42. A vehicle suspensionas set forth in claim 40 wherein said axle center seat comprises aone-piece member bridging said axle side seats.
 43. A vehicle suspensionas set forth in claim 40 wherein said inboard sections are integral withrespective side seats.
 44. A vehicle suspension as set forth in claim 39wherein said axle-supporting surfaces of said side and center seats arecontoured to match the contour of the axle.
 45. A vehicle suspension asset forth in claim 35 wherein said axle-supporting surfaces arecontoured to match the contour of the axle.
 46. A vehicle suspension asset forth in claim 39 further comprising an axle adhesively secured tothe axle-supporting surface of said center seat.
 47. A vehiclesuspension as set forth in claim 35 further comprising an axleadhesively secured to the axle-supporting surfaces of the axle sideseats.